H, 5.85. Found C, 73.54; H, 5.81.3,a-Dimet how-7-p hen y 1-1 1 -oxatricyclo[ 7.3.0.01~o]dodeca-2,4,8-trien-lO-one (13). A solution of 10 (1.59 g, 4.7 m o l ) in dichloroethane (25 mL) was added dropwiee to a stirred solution of rhodium(II) odanoate (0.035 g, 0.047 m o l ) in dichloroethane (25 mL) heated under reflux in an argon atmosphere. After being heated for an additional 12 h, the solvent was removed under reduced pressure and the residue was recrystallized from hexane to give 13 as a colorless solid 0.35 g, 17% yield; mp 126130 "C; IR (CCl,) 1765,1605 cm"; ' H NMR (CDClJ 6 7.37-7.15 (m, 5 H), 6.78 (d, 1 H, J = 1.7 Hz), 4.91 (e, 1 H), 4.72 (d, 1 H, J = 6.7 Hz), 4.34(d,lH,J=8.7Hz),4.29(dd,lH,J=9.3,1.7Hz),4.14 (d, 1 H, J = 8.7Allylic 1,l-dimetaUic species 2, prepared in situ from the propargylic ether 1, are multicoupling reagents. They were allowed to react in a one-pot reaction, with a large variety of electrophiles $-carbonyl compounds (acyl chlorides, aldehydes, ketones, phenyl isocyanate, methyl chloroformate), alkyl bromides, and an amino ether-and then E,-acidic water, iodine, aryl or vinyl iodide in the presence of palladium(0). The isolated yields, based on 1 (5 steps), are fair to good in most cases. The fiist attack (E,) always occurs on the carbon atom a to the oxygen; the second attack (E,) is regio-and stereoselective on the carbon atom a to the TMS moiety.
